a. Field of the Invention
The present invention pertains generally to sawhorses, trestles, and other stands for use as temporary worksurfaces and specifically to brackets for the construction of sawhorses wherein the legs are allowed to fold.
b. Description of the Background
Carpenters, painters, and other individuals who need basic supporting surface that is raised from the floor have used sawhorses as an everyday tool. Scaffolding may be placed on the sawhorses to support workmen as they work, or workpieces may be placed directly on the sawhorses.
Many attempts have been made to create a useful sawhorse, but few inventions have met with much commercial success. Usually, the mechanisms contain many parts, including cross braces and the like, which add to the cost and make the devices less successful in the commercial arena.
Several sawhorses incorporate multiple motions for the legs to rotate, ref U.S. Pat. Nos. 2,431,898, 3,233,701, 3,282,379, 3,631,941, 3,978,943, 4,046,221, 5,439,073, 5,779,003, and 5,813,495. Each of these, in their own way, requires the user to move the legs in two prescribed motions to fold or unfold the legs. The dual motion of the legs adds complexity and cost to the sawhorse. The dual motion has the additional disadvantage of not being intuitive, thus limiting the appeal of the consumer who is likely to purchase the product.
As has been taught in U.S. Pat. No. 3,631,941, it is important for the user of the sawhorse to be able to set the height and size of the sawhorse for the job""s purpose. It is advantageous for the user to select the leg length and thus overall height of the sawhorse without having restriction as to the length. All of the previously referenced patents, as well as U.S. Pat. Nos. 2,520,469, 2,573,740, 3,198,286, 3,618,704 and 3,951,233 do not allow for the legs to be appreciably longer than the main beam of the sawhorse.
Another useful feature for commercial viability is the compactness of the shipping configuration of the sawhorse bracket. Prior art, including U.S. Pat. Nos. 3,978,943 and 5,779,003, do not have this advantage.
The utility of the folding sawhorse depends on the usefulness of the sawhorse in both its folded and unfolded positions. In the folded position, the sawhorse legs should be locked firmly in place so that they do not open when being transported. The assembled sawhorse when folded should be transportable without having to keep the legs from falling open during transport. This allows the tradesman to hold the sawhorse in any position during transport or storage. U.S. Pat. Nos. 2,520,469, 2,573,470, 3,631,941, 3,978,943, 5,779,003, 5,813,495, and D328,355 all teach designs where the legs are locked in the open position but not the folded position.
In the open position, it is also critical for the legs to be firmly and securely braced, as the tradesman may lift the sawhorse by the main beam to reposition it several times during his course of using the sawhorse. A leg that flops around when the sawhorse is picked up is quite distracting and interferes with the tradesman""s job. U.S. Pat. No. 3,978,943 teaches a method where the legs are secured in the open position by the friction of a toothed metal bracket engaging the wooden main beam of the sawhorse. This method would not be adequate for repeated uses, as the wooden beam would become marked by the repeated engagements and would no longer hold the leg securely when the main beam was lifted.
Commercial success is also dependent on the tradesman""s ability to construct the sawhorse quickly and efficiently without having to make complicated compound angle cuts of lumber. U.S. Pat. No. 3,682,272 teaches a design for dually canted pivoting legs, but the construction relies on compound angled cuts.
A simple, intuitive locking mechanism is essential for commercial success of the invention. Tightening fasteners, as in U.S. Pat. No. 3,682,272 is not as desirable as a single press-to-release locking mechanism of the present invention.
For the carpentry trade, the sawhorse is preferred to have the main beam oriented with the smallest dimension of the beam is on the top and contacts the work which rests on the sawhorse. The carpenter also requires that the main beam of the sawhorse is made of wood and does not damage the blade of a saw. This orientation of the main beam also is the orientation that offers the most strength to the sawhorse. U.S. Pat. No. 2,431,898 teaches a device which has metal bracketry which could be damaged by a saw blade. U.S. Pat. Nos. 2,520,469, 2,573,740, 3,198,286, 3,233,701, 3,282,379, 3,631,941, 3,682,272, 3,700,072, 3,951,233, 4,046,221, 4,298,094, 4,967,877, 5,779,003, and 5,813,495 all teach designs which are less desirable in these regards due to the positioning of the main beam.
It would therefore be valuable to provide a bracket to assist the tradesman in building a sawhorse using conventional lumber that allows the legs to fold into a compact unit for transport. Further, the sawhorse bracket should be simple and contain as few a number of parts as possible. The brackets should create a sawhorse that has a simple, intuitive motion for extending and retracting the legs of the sawhorse. The brackets should allow the user to construct a sawhorse of virtually any height and width, with the minimum of restriction. The legs of the sawhorse should lock in place in both the open and closed positions so that the sawhorse is easily repositioned. Further, the bracket should be able to be packaged in a small form for efficient use of shipping and shelf space. The sawhorse should have the main beam oriented with a short side of the main beam at the top to minimize interference with the carpenter""s saw or other tool.
The present invention overcomes the disadvantages and limitations of the prior art by providing a set of sawhorse brackets for building a sawhorse of common dimensional lumber. Further, the brackets create a sawhorse that the legs are foldable and interleave when folded. The legs of the sawhorse rotate in a plane that is doubly canted: first to allow the legs to splay when extended and a slight cant in the plane of the main beam such that the legs do not interfere with each other when folded.
The bracket incorporates two hinge points: a first hinge point where the legs rotate, and a second hinge point where the bracket grips the main beam of the sawhorse. The second hinge point allows the bracket to fold and nest with another bracket so that the pair may be packaged in a box. Further, when the brackets are out the package, the pair will stay together as a unit, for easy handling when the sawhorse is disassembled.
The pivot action of the legs is locked in both the open and closed position using the same mechanism. The locking mechanism is intuitive to a consumer and easy to operate.
The bracket is constructed of two unique parts, four of each are required to make a single sawhorse. The locking mechanism may be constructed of a third part or may be incorporated into one of the other main parts.
The present invention may therefore comprise a bracket for the attachment of a pair of folding legs to a sawhorse horizontal body comprising: a frame for receiving a longitudinal sawhorse body; two leg attachments for each receiving a sawhorse leg, the attachments being pivotally attached to the frame and each being adapted to swing from an extended, service position, to a folded position, the axis of rotation for the first leg attachment being such that the leg forms an acute angle diverging from the axis of the body in the horizontal plane when in the folded position and the second leg forms an acute angle converging to the axis of the body in the horizontal plane when in the folded position.
The present invention may therefore further comprise a bracket for the attachment of a pair of folding legs to a sawhorse horizontal body comprising: a frame comprising two surfaces diverging downward in the vertical plane and canted by an angle in the horizontal plane to a plane normal to the longitudinal axis of the sawhorse horizontal body, the frame adapted to attach to the sawhorse horizontal body, and a leg receiver mounted to each of the diverging surfaces, pivotally mounted and adapted to swing from an extended, service position to a folded position, each leg receiver adapted to receive a sawhorse leg.
The present invention may therefore further comprise a bracket for the attachment of a pair of folding legs to a sawhorse horizontal body comprising: a frame assembly comprised of two frames pivotally attached and adapted to clamp onto the sawhorse main body, each frame comprising a surface diverging downward in the vertical plane and canted by an angle in the horizontal plane to a plane normal to the longitudinal axis of the sawhorse horizontal body, and a leg receiver mounted to the diverging surface, pivotally mounted and adapted to swing from an extended, service position to a folded position, each leg receiver adapted to receive a sawhorse leg.
The present invention may therefore further comprise a foldable sawhorse comprising: a longitudinally extending sawhorse body; two brackets mounted onto the body; two legs pivotally mounted to each of the brackets and adapted to swing from extended, service positions, and positions folded underneath the body; the axis of the pivot mounts being adapted so that the legs clear and lie alongside and at an acute angle relative to one another when in the folded positions.
The advantages of the present invention are the simplicity of the bracket design, which comprises two or three unique parts, and the simplicity of the locking mechanism, both of which result in low per unit cost. The design is intuitive and easily understood by consumers. The bracket uses conventional lumber and does not require any special mitered cuts to produce a fully functional sawhorse. Further, the length of the sawhorse legs is unrestricted, and a sawhorse of any height can be constructed with the inventive brackets. A sawhorse produced with the brackets is sturdy and the legs rigidly lock in both the open and closed positions. The brackets nest into each other so that the packaging for a pair of brackets is simple and space-efficient.